Hearing aid users experience considerable dissatisfaction with hearing aids in noise. Current audiogram-based methods for setting hearing aid parameters (multifrequency gain and compression) are based on predicted loudness and/or intelligibility of speech in quiet; there is no research-based prescription method for setting parameters for speech in noise. At the same time, there is a growing body of evidence that hearing-impaired persons vary considerably in their ability to understand speech in noise, even when their audiograms are very similar. Given this variance in speech understanding in noise, it is reasonable to expect that the variance across hearing aid users in the optimal hearing settings for noisy environments will be at least as large. If this is the case, then the current methods for setting hearing aid parameters for use in noise are almost certainly producing suboptimal results for many hearing aid users. The advent of wireless control of hearing aids provides an opportunity to address directly questions related to the hearing aid parameter settings that users find most beneficial. Availability of a sophisticated system for simulating different sound environments will make is possible to collect a substantial body of data on hearing aid setting preferences in different sound environments that are still under close experimental control. Work proposed here is a systematic exploration of how preferred hearing aid settings vary across hearing aid users and across sound environments. The following hypotheses will be tested: a. Preferred settings are not the same for quiet settings as they are for noisy settings. b. Variance in preferred settings among hearing aid users is larger for noisy settings than it is for quiet settings. c. Preferred noisy settings can be predicted from clinical nd laboratory measures of speech understanding in noise. d. User-adjusted settings will provide greater perceived user benefit in both quiet and noisy situations than settings derived using current clinical practices for setting hearing aids. e. Some users will obtain benefit from hearing aids that allow at-will user adjustments in the field. Overall, results will improve hearing aid outcomes by providing new methods for setting hearing aids for noisy settings, and for allowing users to set their own hearing aids in daily use. Both outcomes have the potential of increasing satisfaction with hearing aids by increasing the perceived benefit of hearing aid settings made in the clinic and in everyday life.